Orthostatic hypotension is an urgent medical problem due to unfavorable clinical manifestations in the form of falls and syncope, difficulties of diagnosis and treatment. One of the factors of importance in hypotension is comorbidity. Orthostasis disorders are widespread among patients with a variety of pathologies. Comorbidity can be the cause of hypotension, aggravate its manifestations and course, and complicate treatment tactics. However, insufficient attention in clinical practice is paid to the study of orthostatic hypotension in comorbidity, and the mechanism of orthostatic syndrome in many cases remains unclear. The prevalence, comorbidity characteristics and regularities of orthostatic hypotension syndrome formation have been studied in the monograph. Possibilities of the complex use of bioimpedance analysis and spiroarteriocardiography for diagnosing orthostatic hypotension and studying its pathogenesis have been evaluated. The possibility of effective non-medicamental correction of hypotension in patients with volumetric disorders in orthostasis has been established. The book is intended for general practitioners, cardiologists, neurologists, researchers.